rs113993986

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2PP3_StrongPP5_Moderate

The NM_002863.5(PYGL):​c.2024C>T​(p.Ser675Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,614,006 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 14/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S675T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

PYGL
NM_002863.5 missense

Scores

18
1

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1O:1

Conservation

PhyloP100: 9.97

Publications

6 publications found
Variant links:
Genes affected
PYGL (HGNC:9725): (glycogen phosphorylase L) This gene encodes a homodimeric protein that catalyses the cleavage of alpha-1,4-glucosidic bonds to release glucose-1-phosphate from liver glycogen stores. This protein switches from inactive phosphorylase B to active phosphorylase A by phosphorylation of serine residue 15. Activity of this enzyme is further regulated by multiple allosteric effectors and hormonal controls. Humans have three glycogen phosphorylase genes that encode distinct isozymes that are primarily expressed in liver, brain and muscle, respectively. The liver isozyme serves the glycemic demands of the body in general while the brain and muscle isozymes supply just those tissues. In glycogen storage disease type VI, also known as Hers disease, mutations in liver glycogen phosphorylase inhibit the conversion of glycogen to glucose and results in moderate hypoglycemia, mild ketosis, growth retardation and hepatomegaly. Alternative splicing results in multiple transcript variants encoding different isoforms.[provided by RefSeq, Feb 2011]
PYGL Gene-Disease associations (from GenCC):
  • glycogen storage disease VI
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia, Genomics England PanelApp, Orphanet, Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.984
PP5
Variant 14-50910048-G-A is Pathogenic according to our data. Variant chr14-50910048-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 21334.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
PYGLNM_002863.5 linkc.2024C>T p.Ser675Leu missense_variant Exon 17 of 20 ENST00000216392.8 NP_002854.3 P06737-1
PYGLNM_001163940.2 linkc.1922C>T p.Ser641Leu missense_variant Exon 16 of 19 NP_001157412.1 P06737-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
PYGLENST00000216392.8 linkc.2024C>T p.Ser675Leu missense_variant Exon 17 of 20 1 NM_002863.5 ENSP00000216392.7 P06737-1
PYGLENST00000532462.5 linkc.2024C>T p.Ser675Leu missense_variant Exon 17 of 20 1 ENSP00000431657.1 E9PK47
PYGLENST00000544180.6 linkc.1922C>T p.Ser641Leu missense_variant Exon 16 of 19 2 ENSP00000443787.1 P06737-2
PYGLENST00000532107.2 linkn.197C>T non_coding_transcript_exon_variant Exon 2 of 4 5

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251462
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000684
AC:
10
AN:
1461830
Hom.:
0
Cov.:
31
AF XY:
0.00000963
AC XY:
7
AN XY:
727218
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.0000464
AC:
4
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111958
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.480
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.0000655
AC:
1
AN:
15276
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1Other:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Glycogen storage disease, type VI Pathogenic:1Other:1
May 24, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: PYGL c.2024C>T (p.Ser675Leu) results in a non-conservative amino acid change located in the pyridoxal-phosphate attachment site (amino acids 673-685; IPR035090) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251462 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.2024C>T has been reported in the literature in multiple compound heterozygous individuals, including two siblings, affected with Glycogen storage disease, type VI (e.g., Beaucham_2007, Davit-Spraul_2011, Luo_2022). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. However, several studies note that the variant is expected to disrupt hydrogen bonding in the active site and therefore is predicted to disrupt enzyme activity (e.g., Beauchamp_2007, Liu_2020). The following publications have been ascertained in the context of this evaluation (PMID: 17705025, 21646031, 35143115, 32961316). No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.49
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.85
.;.;D
Eigen
Pathogenic
1.2
Eigen_PC
Pathogenic
1.1
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
1.0
D;D;D
M_CAP
Pathogenic
0.31
D
MetaRNN
Pathogenic
0.98
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.5
.;.;H
PhyloP100
10
PrimateAI
Pathogenic
0.89
D
PROVEAN
Pathogenic
-5.5
D;D;D
REVEL
Pathogenic
0.94
Sift
Pathogenic
0.0
D;D;D
Sift4G
Pathogenic
0.0
D;D;D
Polyphen
1.0
.;.;D
Vest4
0.93
MutPred
0.92
Loss of glycosylation at S675 (P = 0.0077);.;Loss of glycosylation at S675 (P = 0.0077);
MVP
0.99
MPC
0.51
ClinPred
1.0
D
GERP RS
5.6
Varity_R
0.98
gMVP
0.95
Mutation Taster
=8/92
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs113993986; hg19: chr14-51376766; COSMIC: COSV104576302; COSMIC: COSV104576302; API